A plaque at the gravesite, erected in memory of Sir Thomas Mitchell, the explorer and Surveyor-General of New South Wales. The plaque also commemorates the centenary year of the New South Wales Division of the Institute of Syrveyors.

Sir Thomas Mitchell, Surveyor-General of New South Wales from 1828, led significant expeditions which resulted in charting the `Nine Counties of New South Wales`. He was loyal and encouraging to his parties, yet his Governors found him a difficult man and he had little tolerance for explorers. At the commemoration of the restoration of his grave, Mitchell`s favourite phrase, still in family use, was revealed: "Leichhardt couldn`t find his way up York Street".